I've been looking at the timing tables versus a number of logged timing results. For years there's been the question of why logged timing doesn't always match what's been programmed. EFI now gives us the ability to see where timing is being controlled. In every case where I've looked at my cars logs, there is some point under load that the timing reverts from the high octane table to the optimal timing table. I have not been able to see a definite point except that it seems to happen with increased throttle and above 2000 rpm's. I don't have enough logged information to be sure of what the trigger is.
Two questions:
Anyone know what a definite switch point might be?
Should optimal timing be set the same as the high octane timing, at least in the higher rpm/gpcyl areas?
I suspect that in some cases this situation could be a reason why knock doesn't get solved by reducing timing in high octane.